Vaporizer



Sept. 30, 1952 L, BQDDY 2,612,452

VAPORIZER Filed Dec. 2, 1949 ff@ QW@ f gw y /7 Trai/V575.

Patented Sept. 30, 1952 TENT OFFICE VAPRIZER Leonard Buddy, Ann Arbor,Mich., assignor to King-Seeley Corporation, Ann Arbor, Mich., a

corporation of Michigan Application December 2, 1949, Serial No. 139,796

(Cl. l--llll v 26 Claims. r

The present invention relates to vaporizers and, in the illustratedembodiments, provides such structures wherein material containing orcomposed of an active ingredient is vaporized by the application of heatthereto, and wherein the heat transfer characteristics of the materialare utilized to maintain thev heating action during vaporization and tocause it to be automatically terminated when the vaporizing process hasbeen carried to a predetermined degree oi completion.

In the presently preferred practice of the invention, the aforesaidmaterial is placed in. la container provided with an electric heater.The heater circuit includes a thermally responsive control element whichis heated as a consequence of the flow oi heating current. This controlelement is positioned iny good heat transfer relation to the material,and as specifically disclosed herein, is embedded in the body of thematerial. During the vaporizing action, the material serves to conductheat away from the control element rapidly enough to maintain it belowits critical operating temperature. The vaporizing action, when entirelyor partially completed, however, deprives the control element of thisheat transfer effect and, consequently, the temperature of the controlelement rises to its critical operating point land it opens the heatingcircuit. j

The present vaporizers may, of course, be adapted for use with any of awidev variety of materials such u as insecticides, deodorizers,fumigants, iungicides, Aand the like. In certain instances, as, forexample, in the use of insecticidal paradichlorobenzene, the materialmay be entirely composed of the active ingredient. On the other hand, inthe event the active ingredient is one which is not adapted to performthe heat transfer function, the material may be made up of the activeingredient and a carrier which is capable of performing the heattransfer function. Preferred materials are those Which, While in crystalform, can readily be molded or pressed into cake-like form and which,when subjected to the heat of the vaporizer, pass through a liquidphase. While in the liquid phase, such materials serve eiiectvely asheat transfer agents to maintain the temperature oi the heating controlelement below the critical value.

With the foregoing considerations in View, principal objects of thepresent invention are to provide vaporizers wherein material composed ofor containing an active ingredient is vaporized by the application ofheat thereto and wherein the heat transfer characteristics of thematerial serve to control the heating action; toprovide such structuresWherein-heat is applied under control of an electric circuit containinga thermally responsive element which is heated as a consequence of theyheating action and from which heat is transferred to the materialduring the vaporizing action; to provide such structures wherein thecontrol element is directly exposed to a vaporizable material whichpasses through a liquid phase during the course of the Vaporizingaction;'to provide such structures wherein the control element isinitially embedded in the vaporizable material and is operativelyassociated with the heating control circuit as an incident to theplacing of the material Ain the vaporizer; and to provide'structures ofthe above indicated type which reliably maintain the heating actionuntil the vaporizing action is conrpleted or has progressed to apredetermined degree, and then reliably interrupt the same.

With the above as well as other'and more detailed objects in view, whichappear in the following description and in the appended claims,preferred but illustrative embodiments of rthe invention are shown inthe accompanying drawings throughout the several views of whichcorresponding reference characters are used to designate correspondingparts, and in which:

Figure 1 is a view in vertical 'section' of ay vaporizer embodying theinvention;

Fig. 2 is an enlarged View of the encircled portion of Fig. 1;

Fig. 3 is a View in vertical section of a modified form of theinvention;

Fig. 4 is a View in vertical section, taken alone the line liof Fig. 3;

Fig. 5 is an enlarged view of the encircled portion of Fig. 4; i

Fig. 6 is a view in vertical section of another Lcavity i5 accommodatesthe heater 22.

The illustrated heater 22 is electrical, and comprises an insulated Wire24 wound upona by the partition I2.

piece of insulating material 26, such as mica. Elements 24 and 26 aresupported on a deck 23.

One end of wire 24 extends to one terminal of the illustrated plug 3U,and the other end thereof is connected to a terminal 32 xedly carriedThe companion wire 34 is connected to the other terminal of the plug 30,and to a second terminal 36, fixedly carried by the partition I2.

The vaporizable cake 20 has embedded within it a fusible link 40 and apair of companion terminals 42 and 44 which are, in turn, electricallyconnected to the ends of the link 40.

The cooperating pairs of terminals 32-42 and 36-44 are illustrated asbeing of the plug and jack type. Specifically, terminals 32 and 36 arefemale elements, and terminals 42 and 44 are male elements.

As aforesaid, cake 20 may be formed of or contain an active ingredient.In the case of paradichlorobenzene, for example, the entire cake may beformed of crystals of this material pressed or molded into shape, withelements 40, 42 and 44 embedded therein.

In use, and assuming that cake 2B is positioned as shown, and that thedevice is plugged in, it will be apprecatedvthat current will passthrough the series connected heater 22 and link 45). Heat generated byheater 22 passes through the partition I2 and is absorbed bythe cake 20,thereby elevating its temperaturev and causingY it to liquefy. Theheating current also raises the temperature of the fusible link 40. Thefusing temperatureof this link is, however, well above the boiling pointof the cake material.

With some materials, the heat conducting characteristics` thereof insolid form may be such that heat is conducted away from the link 40through the solid body too rapidly to enable the link 40 to reach themelting point of the cake material. In such cases, the liqueiication ofthe cake material will be due entirely to the heating effect of heater22. The heating effect of heater 22, of course, greatly exceeds that ofthe link 40. In other cases, the solid cake material may not be able toconduct heat away from the linkl 40 fast enough to maintain it below themelting point of the cake material. In such cases, liqueflcation of thecake material will take place progressively from the outside under theinfluence of heater 22 and progressively from the inside under theinfluence of link 40. In either case, the entire cake will be liquefiedbefore link 48 approaches its fusing temperature. As aforesaid, thisfusing temperature is well above the boiling point of the vaporizablematerial.

The continued vaporization of the material ultimately brings the levelof the liquid in cavity I4 to a point below the level of link 40,exposing the latter to atmosphere. TheA atmosphere is, of course, acomparatively poor conductor of heat and, consequently, the continuedflow of current promptly elevates link 40 to its fusing temperature andruptures it, interrupting the heating action.

It will be understood, of course, that after ruptureof the link 40 theused terminals 42 and 44 are withdrawn before the succeeding cake ofvaporizable material is moved into place.

The form of the invention shown in Figures 3, 4, and 5 differs from thatof Figures l and 2, primarily in that the vaporizable cake incorporatesa handle or equivalent element to facilitate the removal of theinitially embedded terminals. The fusible link and terminal structureare received in a well, and the fusible link is provided with a heaterto better insure its maintenance below fusing temperature duringvaporization, and its prompt rupture at the end of the vaporizingprocess.

More particularly, in Figures 3, 4, and 5, the dividing partition 50 isprovided with a depressed central portion 52 which receives that part ofthe cake 54 which encloses the link assembly 56 and the terminals 58 and60. In this instance, terminals 58 and 6D are illustrated as beingfemale terminal elements, and the cooperating fixed terminals 62, and 64are male elements.

Itwili be appreciated that well 52 may be deep enough and narrow enoughto make it difficult for a user to touch the exposed terminals 62 and64, thus improving the safety characteristics of the device. On theother hand, to facilitate removal of the used terminals 58 and B0, afterthe associated cake has beenvaporized, the cake may be provided with theillustrated embedded handle 63, the lower ends` of which are connectedto but insulated from the terminals 58 and 60.

In this instance, the control assembly 56 comprises the fusible link 66,and a heater therefor comprising the insulated length of wire 68. Coil68 and link 6B are connected in series between terminals 58 and 60..

As in the case of Figure 1, until such a time as the level of thevaporizable material falls below the level of the link assembly 5B, thetemperatures of elements 66 and 68 are maintained well below the fusingtemperature of link 66. Dependingupon the heattransfer characteristicsof the material, liqueflcation of the material may take place entirelyunder the influence of the external heater 22 or partly under theinfluence of the fusibleassembly 56. In either event, as soon asassembly 56 is exposed to atmosphere, coil 68 is enabled to promptlyelevate link 66 to its fusing temperature, thereby rupturing the same.By virtue of the series connection between link 66 and coil 68, thefusing of link 66 interrupts the heating action.

The form of the invention shown in Figures 6 and 7 may, if desired,embody the well and handle construction of Figures 3, 4, and 5, but isillustrated as embodying the construction of Figures 1 and 2 with theexception that the fusible link 40 is replaced by an interrupterassembly 10. Assembly 10 comprises a bimetallic element 12, whichcarries an insulated heater coil 14. Bimetallic element 12 also carriesa moving contact 16, which normally engages a fixed contact 18.. Contact18 is carried by, but insulated from, a supporting member 80, which alsoserves as a support for element 12,. One spring-like end 82 of support80 is laterally turned and, when the contacts 16--18 are closed,overlies the end of element 12. Heating of element 12, of course,causes. it to, warp downwardly as viewed in the figures and separate thecontacts, enabling the spring-likeportionSZ to move into blockingrelation to element 12 and prevent a reclosure of the contacts 16,-18.

One end of heater 14 is connected to terminal44, and theother endthereof is connected to moving contact 16, either directly or throughthe body of the bimetallic element 12. The stationary contact 18 iscontinuously connected to the remaining terminal 42. With this relation,the heater circuit includes in series the primary heater 22, heatingcoil 14, and contacts 16-18.

As before, the interrupter assembly 1|] is embedded in the cake 20 as anincident to the initial formation thereof. In such embedding process, itis, of course, preferred that the crystals of vaporizablematerlalentirely surround and enn gage all surface areas of the assembly 1G.

In operation, assuming the calze 20 is in place in the vaporizer, andthe unit is plugged into a source of supply, the main heater-22 acts toheat the cake 20 as a whole and liqueiies the same. The heating currentalso flows through the bimetallic heater T4, enabling it tol heat thebi- Inetallic element 12. Depending upon the heat transfercharacteristics of the vaporizable cake 2B, it may extract heat from theinterrupter assembly 'l0 rapidly enough to maintain it below the meltingpointof the vaporizable material, in which event the liquefaction of thelatter takes place from the outside in towards the center. In otherinstances, assembly T0 may ultimately reach a temperature above themelting point of the vaporizable material, before the latter has becomeentirely liquefied. Even in such instances, several factors contributeto prevent the opening of contacts 'iS-l until the material has beenvaporized to a point at which the level of the liquidV in the containeris below the level of assembly 1E.

In the iirst place, at least until the material immediately surroundingbimetallic element l2 has liquefied, the material itself is effective tomechanically restrain bimetallic element 12 and prevent it fromseparating the contacts 'I6-Slt.

In the second place, the heat capacity of element 12, the heating effectof heater lll, and the heating effect of the main heater 22, may be sorelated to the heat capacity of the cake 2B as to insure thatliquecation of the calze has taken place before element 12 has absorbedenough heat from heater 'M to open the contacts. perhaps controllingimportance, the temperature at which bimetallic element l2 openscontacts f6- 18 is `set well above the boiling point of the liquidvaporizable material. Consequently, contacts I6-JIS remain closed untilthe vaporizlng action has been completed, or :substantially so. Whenthis stage is reached, assembly l@ becomes exposed to atmosphere,enabling heater 'M to rather `promptly bring bimetallic element l2 uptoits critical temperature at which it opens its contacts 15S- '18 andinterrupts the heating action. As aforesaid, finger portion 82 ofsupport 80 springs into the path of element 'l2 when the latter openscontacts ifi-IES, and prevents a reclosure thereof.

Although only several embodiments of the invention have been describedin detail, it will be appreciated that various further modifications inthe form, number, and arrangement of the parts may be made withoutdeparting from the spirit and scope of the invention.

What is claimed is: r

l. A vaporzing device comprising a container for receiving vaporizablematerial which is normally in solid form but which is vaporizable uponthe application of heat, thermally responsive control means normallyembedded in and carriedr by said material in heat exchange relationtherewith and having a critical operatingr temperature, means forsupplying heat to said' material to vaporize it and to said element atsuch rate as to be normally effective to raise it to said criticaloperating temperature, said material having a vaporizing temperaturebelow said critical temperature whereby said material is effective byVirtue of said heat transfer relation to maintain the temperature ofsaid control means below said critical temperature until thevaporization of said Finally, and of material has progressed to apredetermined degrec, said control means being eiective when it reachessaid critical temperature for reducing the heat supplied by said'heatsupplying means, and means forminga releasable heat energy transferconnection between said control means and said supplyv means wherebysaid control means may be removed prior to the placing of a fresh chargeof new material into said container.

2. The structure of claim 1 wherein said thermally responsive controlmeans is positioned in the body of said material in direct conductiveheat transfer relation thereto.

3. The structure of claim 1 wherein said heat supplying means includesan electric heating element for supplying vaporizing heat to saidmaterial and said control means includes an electrically conductiveelement connected to receive heating current concurrently with saidheating element, said control means eecting said control by interruptingsaid flow of heating current.

4. The structure of claim l wherein said control means includes afusible link disposed to receive heating current, and means renderingthe fusing of said link effective to reducethe heat supplied by saidheat supplying means.

5. The structure of claim 1 wherein said control means includes afusible link and an electrically conductive heater therefor disposed toreceive heating current, and means rendering the fusing of said linkeffective to reduce the heat supplied by said heat supplying means.

6. The structure of claim l wherein said conw trol meansvincludes amember having a portion which moves in response to changes in itstemperature, and a heater therefor, and means rendering movement of saidportion effective to reduce the heat supplied by said heatV supplyingmeans.

'7. The structure of claim 1 wherein 'said control means includes amember having a' portion which moves in response to changes in itstemperature, circuit controlling contact means actuable by said movementof said portion, an electrically conductive heater forsaid member, andmeans rendering the energization of said heat supplying means and saidheater subject to said contact means.

8. The structure of claim 1 wherein said control means includes a memberhaving a portion which moves in response to changes in its temperature,circuit controlling contact means actu able from a first circuitcontrolling position to another by said movement of said portion, anelectrically conductive heater for said member, means rendering theenergization of said heat supplying means andsaid heater subject to saidactuation of said contact means, and means effective after a saidactuation for preventing a return of said contact means to said firstposition.

9. A vaporizing device comprising a container adapted to receive a bodyof vaporizable material normally in solid form, a thermally responsiveelectrically conductive control means carried by and positioned withinsaid material and in direct conductive heat transfer relation to saidmaterial, electric heating means carried by said container and arrangedto supply heat to said material, means adapting said heating means andsaid control means for connection to a source of current so as toconcurrently receive heating current at rates suflicient, respectively,to vaporize said material and, normally, to actuate said control means,said adapting means including a partable connection one portion whereofaeiaaaa being carried ,by said container'and another portion whereofbeing carried by `said material, said control means' when actuated beingeffective to interrupt said fiow of heating' current, said materialhaving a vaporizing temperature below said critical temperature wherebysaid material is effective by virtue of said heatA transfer relation tomaintain the temperature of said control means sumciently low to preventsaid actuation thereof until the vaporizati'on of said material hasprogressed to a predetermined degree.

10. The structure of claim 9 wherein said control means comprises afusible link, fusing whereof interrupts said flow of heating current.

11. The structure of claim 9 wherein said control means comprises afusible link and an electrically conductive heater therefor, fusion ofsaid link serving to interrupt the ow of current to said heater and saidheating means.

12. The structure of claim 9 wherein said control means comprises amember having a portion which moves in response to changes in itstemperature, an electrically conductive heater therefor, and meansresponsive to movement of said portion for interrupting the ow ofcurrent to said heater and said heating means.

13. The structure of claim 9 wherein said control means comprises amember having a portion which moves in response to changes in itstemperature, an electrically conductive heater therefor, meansresponsive to movement of said portion for interrupting the flow ofcurrent to said heater and said heating means, and means forming part ofsaid control means for maintaining said interruption after cessation ofthe flow of heating current.

14. A vaporizing device comprising a container for receiving a body ofvaporizable material, which body carries a thermally responsive circuitcontrolling element and terminals leading thereto, said devicecomprising an electric heating element, partable spaced terminals forelectrical connection to saidrst-mentioned terminals when the body ofthe material is positioned in the container, one of said terminals beingcarried by said material `and another of said terminals being carried bysaid container, |and circuit means adapting said electric heatingelement for connection to a source of power in series with saidterminals.

15. As an article of manufacture, a body of vaporizable material, athermally responsive circuit controlling device carried by said body forand connectible between associated supply terminals of an associatedvaporizing device.

16. The article of claim wherein said circuit controlling elementcomprises a fusible link and an electric heater therefor and connectedto receive current through said link.

17. The article of claim 15 wherein said circuit controlling elementincludes a thermally responsive member having a portion which moves inresponse to changes in temperature, contact means controlled by saidmovement, and an electric heater for said member connected to receivecurrent under control of said contact means.

18. The article of claim l5 wherein said circuit controlling elementincludes a thermally responsive member having a portion which moves inresponse to changes in temperature, contact means controlled by saidmovement, an electric heater for said member connected to receivecurrent under control of said contact means, and

means for maintaining said circuit in interrupted condition, afterinterruption thereof.

19. As an article of manufacture, a body of vaporizable materialdisposed to be positioned in a container and to receivevaporizing heattherefrom, a thermally responsive control element carried by said bodyin direct conductive heat transfer relation thereto, and connectingmeans for said element carried by said body and having exposed portionsadapted to make an operative connection with associatable means carriedby said container.

20. As an article of manufacture, a body of normally solid vaporizablematerial, a thermally responsive circuit controlling device carriedwithin said body, terminals carried by said body and connectible withassociated supply terminals of an associated vaporizing device.

21. A vaporizing device comprising a container for receiving avaporizable material which is normally in solid form but which isvaporizable at a temperature below a critical temperature upon theapplication of heat, said container having a heater associated therewithfor supplying heat to said material, a control circuit for said heaterand having control terminals facing the interior of said container forassociation with thermal responsive control means originally embedded insaid material and releasably contactable with said terminals upon theplacing of said material in. said container, means for supplying asource of energy to said terminals whereby said thermal means is heatedindependently of said heater at a rate such that when said thermal meansis in heat exchange relation with said material said thermal means ismaintained below said critical temperature and maintains said heaterenergized, said rate being such that when said thermal means is not inheat exchange relation with said material said thermal means becomeselevated above said critical temperature to de-energize said heater.

22. The combination of claim 21 in which said terminals are female andare located adjacent the bottom wall of said container.

23. The combination of claim 2l in which the bottom wall of saidcontainer is provided with a recess and` said terminals are in saidrecess.

24. A vaporizing device comprising, an upwardly facing cup-shapedcontainer having av bottom wall and adapted to receive a body ofnormally solid material vaporizable upon application of heat theretobelow a critical temperature, a pair of electrical terminals carried bysaid container, said body having a bottom surface. heating meanssupplying heat to said body, a thermal responsive control means withinsaid body adjacent said bottom surface and controlling the energizationof said heating means, contacts carried by said body and connectiblewith said first-named terminals with said body in said container, saidheating means supplying heat to said body at such a rate that saidmaterial will vaporize below said critical temperature and therebymaintain the temperature of said control means below said criticaltemperature, said heating means rate being sufficiently great wherebywhen said material is substantially vaporized the temperature of saidcontrol means will increase to said critical temperature, said controlmeans acting at said critical temperature to terminate the heatingeffect of said heating means.

25. The combination of claim 24 in which said heating means iselectrically energized.

26. A vaporizing device comprising, an upwardly facing cup-shapedcontainer having a bottom wall and adapted to receive a body of normallysolid material Vaporizable upon application of heat thereto below acritical ternperature, a pair of electrical terminals carried by saidcontainer and facing the interior of said container bottom wall, saidbody having a bottom surface adapted to rest on said bottom wall,heating means supplying heat to said body, a thermal responsive controlmeans Within said body adjacent said bottom surface and controlling theenergization of said heating means, contacts carried by said body bottomsurface and connectible with said first-named terminals upon insertionof said body in said container, said heating means supplying heat tosaid body at such a rate that said material will vaporize below saidcritical temperature and thereby maintain the temperature of saidcontrol means be- 20 at said critical temperature |to terminate theheating effect of said heatingvrneans.

LEONARD BODDY.

REFERENCES CITED The following references are of record in the file ofthis patent: l

.UNITED STATES PATENTS Number Name Date Re. 21,232 Van Dyke Oct. 10,1939 1,022,016 Andrews Apr. 2, 1912 1,561,243 Keene Nov. 10, 19251,718,412 Crooker et al June 25, 1929 1,907,845 Macrae et al May 9, 19332,000,266 Watson May 7, 1935 2,504,460 Slatkin Apr. 18, 1950 FOREIGNPATENTS Number Country Date 154,194 Great Britain Feb. 20, 1922 194,572Great Britain Mar. 15, 1923 515,562 Germany Jan. 7, 1931 519,684 GreatBritain Apr. 3, 1940

1. VAPORIZING DEVICE COMPRISING A CONTAINER FOR RECEIVING VAPORIZABLEMATERIAL WHICH IS NORMALLY IN SOLID FORM BUT WHICH IS VAPORIZABLE UPONTHE APPLICATION OF HEAT, THERMALLY RESPONSIVE CONTROL MEANS NORMALLYEMBEDDED IN AND CARRIED BY SAID MATERIAL IN HEAT EXCHANGE RELATIONTHEREWITH AND HAVING A CRITICAL OPERATING TEMPERATURE, MEANS FORSUPPLYING HEAT TO SAID MATERIAL TO VAPORIZE IT AND TO SAID ELEMENT ATSUCH RATE AS TO BE NORMALLY EFFECTIVE TO RAISE IT TO SAID CRITICALOPERATING TEMPERATURE, SAID MATERIAL HAVING A VAPORIZING TEMPERATUREBELOW SAID CRITICAL TEMPERATURE WHEREBY SAID MATERIAL IS EFFECTIVE BYVIRTUE OF SAID HEAT TRANSFER RELATION TO MAINTAIN THE TEMPERATURE OFSAID CONTROL MEANS BELOW SAID CRITICAL TEMPERATURE UNTIL THEVAPORIZATION OF SAID MATERIAL HAS PROGRESSED TO A PREDETERMINED DEGREE,SAID CONTROL MEANS BEING EFFECTIVE WHEN IT REACHES SAID CRITICALTEMPERATURE FOR REDUCING THE HEAT SUPPLIED BY SAID HEAT SUPPLYING MEANS,AND MEANS FORMING A RELEASABLE HEAT ENERGY TRANSFER CONNECTION BETWEENSAID CONTROL MEANS AND SAID SUPPLY MEANS WHEREBY SAID CONTROL MEANS MAYBE REMOVED PRIOR TO THE PLACING OF A FRESH CHARGE OF NEW MATERIAL INTOSAID CONTAINER.